This invention generally relates to cooling devices such as heat exchangers and, particularly, to a heat sink retainer and a heat sink assembly using the heat sink retainer to dissipate heat from heat generating components.
In various industries, such as in the computer industry, there is a need for low cost high performance heat exchangers to cool such components as microprocessors or semiconductors. Many semiconductors create so much heat that they can be irreparably damaged if the heat is not removed. Consequently, heat exchangers employing heat sinks have been used to pull the heat away from the semiconductor and disperse that heat into the atmosphere. However, prior art heat sinks have generally been configured in such a manner that the air flow is either unidirectional or bidirectional, thereby making them susceptible to recirculating the heated air on or near the component(s) to be cooled. The present invention is directed to improvements in such heat sink retainers and heat sink assemblies.
An object, therefore, of the invention is to provide a new and improved heat sink retainer and heat sink assembly of the character described.
In one embodiment of the invention, the heat sink assembly used to dissipate heat from a heat generating component includes a heat exchanging section having a thermally conductive sheet folded into alternating ridges and troughs defining spaced fins having first and second end edges. The folded sheet is formed into a generally cylindrical configuration defining an axis. The troughs form an inner segmented cylinder, the ridges form an outer segmented cylinder generally concentric with the inner cylinder and the fins radiate outwardly from the axis, thereby allowing air to be circulated in all directions and not just the unidirectional or bidirectional pattern common in prior art heat exchangers. A thermally conductive core is provided within the inner segmented cylinder defined by the troughs of the cylindrically folded sheet to transfer the heat to be dissipated from the heat generating component to the heat exchanging section. A retainer is engaged with the cylindrically folded sheet generally at the second end edges of the fins to retain the cylindrically folded sheet about the periphery of the core.
As disclosed herein, the retainer includes a circular top portion for engaging the cylindrically folded sheet at the second end edges of the fins. A plurality of fingers depend from a peripheral edge of the circular top portion and are individually engageable with at least some of the ridges of the cylindrically folded sheet. At least some of the ridges include apertures that serve the dual purpose of allowing additional air flow through the fins and for receiving latch detents on the insides of respective ones of the fingers. At least one stop projection extends from the top portion between an adjacent pair of the fins of the cylindrically folded sheet to prevent rotation of the retainer relative to the heat exchanger.
The invention contemplates that the assembly may include a base plate above which the heat exchanging section is mounted. The first end edges of the fins of the cylindrically folded sheet are disposed between the base plate and the second end edges of the fins. Additionally, a peripheral shoulder on the core may be employed to raise the heat exchanging section off of the base plate so that the first end edges of the fins of the cylindrically folded sheet are spaced from the base plate. Complementary interengaging latch means are provided between the retainer and the base plate to hold the heat exchanging section therebetween.
The complementary interengaging latch means includes a latch arm depending from the retainer on the outside of the cylindrically folded sheet. A latch flange projects upwardly from the base plate. A resilient latch hook on one of the latch arm or latch flange snappingly engages in a latch opening in the other of the latch arm or latch flange.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.